Luminaires for interior lighting are often designed for aesthetic appeal when directly viewed, as well as for providing high quality illumination. Related design objectives can include providing visually interesting components such as a housing and/or other structural components or light scattering or diffusing type elements. Typically, the actual light-emitting devices within luminaires are more or less exempt from such design objectives, because viewers generally will not be looking directly into the light-emitting devices due to discomfort. However, other elements within fixtures can provide visual interest as well as shielding viewers from high-angle light output (glare). Certain other features often present in luminaires, but which may be regarded as distracting, include optical surfaces that form angles. Optical performance typically changes noticeably across such angles such that a viewer's eye is drawn to them, instead of the luminaire simply providing gradually or continuously changing luminous intensity across the visible area of the luminaire.